Log Message:
Updated fontconfig to 2.12.1.

I've released 2.12.1 containing some fixes:
- IMPORTANT: properly validate offsets in cache files. see changelog and
  CVE-2016-5384 for more details. thanks to Tobias Stoeckmann for catching
  this up!
- build issues regarding to Python.
- add --with-default-hinting to configure.
- fix segfault in FcWeightFromOpenType()